The invention relates to a Resource Manager, and more particularly, to a technique for scheduling multiple disk requests with guaranteed completion times and writing data buffers to disk to free memory.
As electronic imaging machines become more complex and versatile in operation, there is a greater demand for higher performance and expectations from limited resources. A suitable control must be able to not only coordinate the operation of the various components of the machine such as the scanner and the printer but must also be able to schedule and allocate key control elements such as random access memory and disk or mass memory to provide the most efficient and productive operation of these components.
In the prior art, U.S. Pat. No. 4,589,093 discloses a Timer Manager for suspending tasks waiting for switch or sensor input, or waiting for a real time or machine clock delay. U.S. Pat. No. 4,338,023 teaches a technique of job recovery employing the efficient use of machine resources depending upon the type of recovery required and the particular use of the resources. U.S. Pat. No. 4,800,521 discloses a task control manager for executing a plurality of tasks concurrently.
A difficulty with the prior art machine systems is the need for sufficient memory to handle high speed resources concurrently such as scanning and printing or alternatively the need for an adequate resource manager to handle such operations. Often, the insufficiency of memory space results in error messages or re-requests to the control for memory allocation resulting in delay and prolonging of the reproduction or printing cycle. It would also be desirable to be able to provide a scheme to resolve multiple requests for memory and be able to guarantee memory availability at a predetermined time.
It is an object, therefore, of the present invention to guarantee the time when memory or a mass memory access can be completed. Another object of the present invention to predict when memory will become available and to provide requesters of memory space guaranteed time of memory availability in order that the requesters can determine a further course of action. Other advantages of the present invention will become apparent as the following description proceeds, and the features characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.